1. Technical Field
Embodiments of the present disclosure relate to a liquid supplying device to supply liquid, such as ink, stored in a liquid storage unit to a liquid supply target and an image forming apparatus, such as a printer, a copier, or a facsimile machine, including the liquid supplying device.
2. Description of the Related Art
A liquid supplying device may have a pump called a diaphragm pump including a first check valve and a second check valve arranged at an inlet, through which liquid is supplied into a diaphragm (liquid container), and an outlet, through which liquid is discharged from the diaphragm, respectively. The diaphragm includes a compression coil spring (hereinafter, referred to as “spring”) to urge the diaphragm outward. When the diaphragm is expanded outward by the urging force of the spring, the internal volume of the diaphragm increases. The diaphragm pump has a pressing member to press the diaphragm inward from the outside of the diaphragm against the urging force of the spring.
When the pressing member turns into a pressing state in which the pressing member pressing the diaphragm from the outside, the volume of the diaphragm decreases. As a result, the internal pressure of the diaphragm rises, thus discharging liquid from the outlet of the diaphragm via the second check valve. By contrast, when the pressing state of the pressing member is released and turned into a non-pressing state, the volume of the diaphragm is raised by the spring of the diaphragm. As a result, the internal pressure of the diaphragm falls, thus supplying (sucking) liquid from the inlet of the diaphragm via the first check valve. For example, such a diaphragm pump is employed as a liquid feeding unit to feed ink as liquid from a main tank (liquid storage unit) to a sub tank (liquid supply target) in an inkjet recording apparatus.